I was used to using the MultiSearchRequestBuilder back in 2.x to submit multiple search requests in bulk. My search requests came from JSON files.
In 5.x, my requests are still built in JSON files, but now it seems I have to use SearchTemplateRequestBuilder. Those work well on their own, but I don't know how to add these in bulk for a bulk search. There is a MultiSearchTemplateRequestBuilder class, but I don't know how to "prepare" it. I would have expected a ...client().prepareMultiSearchTemplateRequestBuilder() however that doesn't exist (as of 5.1.1).